Alloy



Patented (Bet 26, 1937 ,tmi

Anthony a. do Golyer, New York, N. Y.

No Drawing. Application August 24, 1936,

Serial No. 97,593

2 clai s.

amenable to thermal treatment, by means of which the hardness, tensile strength, cutting efficiency and other physical properties and char-' acteristics may be accurately controlled over comparatively wide range.

I have found through experiment that by alloying or otherwise intimately combining boron, chromium, vanadium and nickel within the range of boron 0.50% to 3%, chromium 8% to vanadium 1.50% to 8%, and nickel sub- I stantially the balance, that I obtain metallic compositions which possess in combination materially improved physical properties compared to those of heretoforeknown alloys or compositions intended for the cutting or-working of metals;

Alloys of this invention may be used in the cast condition but approximate maximum values of hardness, resistance to impact and certain other important physicalproperties can be developed only through thermal treatment, or

have been subjected to such treatment are particularly valuable for use as tools, dies and the like for the cutting or mechanical working of metals.

40 Numerous metallic compositions have heretofore been proposed as improvement on the gen-' tools. Sintered or semi-fused compositions containing principally carbides of tungsten, molybdenum or tantalum bonded with a relatively soft matrix metal have a high degree of hardmess, but are extremely brittle. Cast compositions of the types heretofore proposed require 65 the presence'of at least 1.50% carbon to qualify superior to that of present known high speed,

through mechanical working and subsequent, thermal treatment. Bodies of the alloys which.

as metal cutting tools and, as is well known, such alloys are not only brittle, but are so sensitive to various operating conditions as to greatly restrict the scope of usefulness. One of the greatest disadvantages of the heretofore proposed compositions is that none .of them are responsive to thermal treatment for regulation of physical properties, and consequently physical properties and characteristics are governed entirely by the chemical composition of the sintered or cast material.

My alloy may be used in the as-cast .condition, or it may be forged and rolled or otherwise mechanically worked. I have found that both the cast and forged material are amenableto thermal treatment. For example, cast bodies of this alloy may have ahardness of from to on the Rockwell C. scale and by subjecting the material to suitable thermal treatment, such as quenching .from a temperature higher than approximately l000 (3., the hardness may be loweredto' an approximate range of from 40 to 47 Rockwell C. In this condition the bodies may be ground, shaped or formed, as desired. -The alloy may subsequently be submitted to a second. thermal treatment, such as heating to a temperature of less than 1000 C. for a period of one hour or more, by which the hardness may be increased to' from approximately 60 to Rockwell C. In the latter condition the alloy is especially valuable for ,the cutting or mechanical working of a large number of metals and alloys, as well as numerous non-metallic materials. An important property'of the alloy j resistant to failure from sudden or repeated shock. Therefore, tools made of the present alloy retain an eillcient' cutting edge for longer periods than other tools.

The .more important distinctive and valuableadvantages are, apparently, due to the presence of appreciable amounts of boron in thecomposition..in conjunction with the other essential comcially after thermal treatment, it is remarkably ponent elements within the percentages specified herein. Specific examples of compositions within the scope of the present-invention which I have found well adapted for metalcuttlng tools, dies chromium 13%, vanadium. 6%, nickel balance; boron 2.10%, chromium 20%, "vanadium 4%, nickel balance.

An objective of the present invention is to provide alloys having high hardness, advantageous metal cutting properties, etc., which are free or substantially free from carbon, and thus eliminate all of the serious disadvantages assoence of appreciable amounts of carbon decreases the red hardness of the alloy, 1. e; hardness at temperatures of approximately 550, C. and

5 higher.

Byheason of the fact that theelements form:

ing the essential components of the alloy of the present invention invariably are contaminated with other elements when produced in commercial quantities, the alloysof my invention usually contain insignificant amounts of one or moreelements in the nature of impurities incidental to manufacture. The amount ,of such impurities should be restricted to percentages which are not effective on the physical properties or character-- istics of the alloy, nor on the physical reactions during thermal treatment. I have found'that the amount of any one of such incidental impurities should not exceed a maximum of 1%.

The presence of larger amounts of such impurities, particularly silicon and aluminum, materially decreases the resistance of the alloy' to failure under shock and impact during cutting operations, and, further, inhibits the desired physical reactions during thermal treatment.

097,181 [and the like'are the following: boron 1.20%,

Therefore, the presence of eflective amounts of impurities, such as carbon, silicon and aluminum, act to appreciably lower the cutting efllciency and general value of the present alloy.

My investigations indicate that the preferred structure of a body of the present alloy, particularly after thermal treatment, comprises at least two principal constituents: one, arelatively hard intermetallic compound of boron with one or more of the other essential components; and second, a solid solution of two or more of the essential components which has a lower degree of hardness and functions as a matrix. In some instances the structure will contain a third constituent in the nature of an eutectoid. The ratio of the constituents and the ratio of particle size in any particular body of the alloy may be accuratelycontrolled and fixed over a wide range by means of thermal treatment, or mechanical working and subsequent thermal treatment.

By reason of the combined advantageous physical properties possessed by the alloy of the present invention, tools and other articles composed of. this alloy may beoperated efilciently and economically under conditions which are impose sible or uneconomical with tools or other articles composed of heretofore known alloys or metallic compositions.

By the term "the balance substantially nickelf in the foregoing and in the following claims, I intend that the alloy of the present invention comprises boron, chromium and vanadium within the percentage limits specified, with theremainder-nickel except for'inefiective amounts of impurities which may be present incidental to manufacture.

I claim: I

1. An age hardened alloy containing boron o.5o% to 3%, chromium 8% to 30%, vanadium 1.50% to 8%, the balance substantially nickel.

2. An age hardened alloy characterized by being responsive to thermal treatment for effecting precipitation hardening comprising boron 0.50% to 3%, chromium 8% to 30%, vanadium 1.50% to 8%, the balance substantially nickel.

ANTHONY G. n: GOLYER. 

